One coat plasters are the coats of plaster that you will probably end up using most often because they can function as both an undercoat and a finish.
They are widely used as an undercoat and as a finish by those renovating old houses or renovating new houses for which they want an old world look. It consists of lime putty and sand mixed with water until you achieve a demarcation between what is wet and what is dry. This is then applied to the surface of whatever is to be plastered and then carved by hand or feel into whatever pattern you desire.
However, if more than one layer of plaster is applied, the weight of the structure might increase to a considerable amount causing damage to the building. So it is advisable that you use single coat plaster for indoor walls and two layers on outdoor walls with sunlight exposure.
Generally, one coat is used for repair jobs as it is a lot easier to get a smooth finish over smaller areas.
